/Engine/Source/Editor/MaterialEditor/Public/MaterialEditorUtilities.h
Creates a new material expression of the specified class on the material represented by a graph.
static [UMaterialExpression](API\Runtime\Engine\Materials\UMaterialExpression) * CreateNewMaterialExpression ( const class [UEdGraph](API\Runtime\Engine\EdGraph\UEdGraph) * Graph, [UClass](API\Runtime\CoreUObject\UObject\UClass) * NewExpressionClass, const FVector2D & NodePos, bool bAutoSelect, bool bAutoAssignResource )